Description
Fields is for curve, surface and function fitting with an
emphasis on splines, spatial data and spatial statistics. The
major methods include cubic, robust, and thin plate splines,
and Kriging for large data sets. The splines and Kriging
methods are supporting by functions that can determine the
smoothing parameter (nugget and sill variance) by cross
validation and also by restricted maximum likelihood. A major
feature is that any covariance function implemented in R with
the fields interface can be used for spatial prediction. Some
tailored optimization functions are supplied for find the MLEs
for the Matern family of covariances. There are also many
useful functions for plotting and working with spatial data as
images. This package also contains an implementation of a
sparse matrix methods for large data sets and currently
requires the sparse matrix (spam) package for testing (but not
for the standard spatial functions.) Use help(fields) to get
started and for an overview. The fields source code is heavily
commented and should provide useful explanation of numerical
details in addition to the manual pages.